They are super easy to do. I put my center caps, one at a time in mildly boiling water for about 1-2 min. Do not let them touch the bottom of the pan and seriously no longer than a min or two-they will warp.

Buy stickers from Doc and you can get rid of the Rota 'R' heh

You lost me when you talked about boiling them? Is that to make application easier or removal of the stickers easier?